Electrically operated clock



Sept. 1, 1931. 1.. J. STERN 1,821,320

7 ELECTRICALLY OPERATED CLOCK Filed Feb. 8, 1926 2 Sheets-Sheet l gt: -77 Z0, 2 Z fife Z5 v J 5 j 35 awueutoz Sept. 1,-1931. L. J. STERN 1,821,320

ELECTRICALLY OPERATED CLOCK Filed Feb. 8, 1926 2 Sheets-Sheet 2 351 his flbtommf i atented Sept. 1

" o STATES 'PATENT Fries LEWIS STERN, or new EORK, ma Y; SsiG NoR *TdiSTERLING 'cnocgfleo. Inof. ii

coeromrion or NEW YORK nLno'TRxoAnm-i OPERATED CLOCK Application filed February 8,1926. serial life/$6,766.

/ operation. :Fnr-t her and more specific ob iects, features and advantages will more clearly appear, from the detail description given below taken in connection with the acooinpanyi-n drawings which form a part of this specification.

Int e drawingfs'Fig. lis a face view of a clock embodying-ray improvements in one form. I

Fig. 2 is a side elevationai View of the dock parts with portions of the outer-casings removed or-shoWn in section.

Fig. 3 is asection a1 View of the sameciock, this section being taken substantially along line 33 of Fig. 2.

4 is a further sectional view-taken substantially alon the line 4.--4 of Fig. 2.

Fig. 5 is a top nv-iew showing the exterior of the same clock. I

'Fig'. 6 is a detail elevationai View taken I in direction indieatedby the arrows 6-43 of Fig. 3 and also showing a portion of the clock casing in section.

Big. 7 a detail view'iaken in a direction indicated by the arrows 77 of Fig. v

Fig. 8 is a detaii sectional View ta-ken'snbstantiaiiy along the line 88 of Fig. 3.

Fig. 9 is enlarged View-showing a portion of Fig. 3. I

Referring to the drawings, a clock casing or housing is indicated at 10. This casing may be of a type adapted to be mounted upon the instrument panel or dashboard of an automobile and may comprise a body on 11 for receiving the *electro-magne 1c clock and mechanism hereinaiieer described. The forwardportion of the casing 1-0 may be formed with an outwardly ex- -t iiding flange hayin its periphery of a shape cor-responding to and harmonizing This enlarged flange portion mrn .restsegainst the clock face at its periphery, which glass may beretained inplaee by suitable beaded flanged member 15: criniped at 1'6 overa fianged member 17 which teleseopi y-receives the flanged casing. The flai med meinber .17 maybe retained in poi] oenpongthe casing by means of screws 18 which are. provided with nuts as-at 1-9,

the 'zeipherai edges of "which protrude through adjacent slots "in the flanged i member 17 (seeFigiines1and 2). y i j A suitable clock mechanism o f any preferred OOIYYQIHZiOQZLL fiOHE may be used and is indicated :at 29. This mechanism may 'be retained within a frame 'work comprising platesfll andQQ held in spaced relation by CQHHECtiIl gTPOSfiS as at The plate 21 may be provided with a suitable flanged resees for receiving the clock mechanisnnsuch 'mechanism being retained in the recess screws as zit-24. j p a V The electromagnetic operatmg mecha 'nlsm hereinafter described isinounted atthe front and rear taceszof ithe plate The parts monntednponthe rrontface as shown 4: .vvi'llbefirst descrirhed. The main .clociiwarbor 25 provided with ratchet Wheel 26 adjacent the plate 22. For operatin-grzafcloek set the type indicated, this angle represented by one tooth each minute so that; the Wheel makes one eomp lete revolotion per, hour. uaily exerted against the ratchet wheel by means ofa pawl 27 which is urged into Contact with the ratchet teeth by'a spiral spring '28. This spring comprises-What may be termed the main spring. The mechanism now being described maybe termed a spring motor and it will be understood I that when reference is made to the spring with the other instruments on thedeshboard if, desired. nayprovide areeess 12 Within which the clock face plate l i-lznay be piaced with its periphery resting against the-flangeof the ,cioe-kiiasing; A glass cover plate A Tanning force ,is continas being wound, this is intended to mean that the spring is under tension. When the spring motor is referred to as being unwound, the spring 28 will also be under tension but will be contracted to a considerable extent as compared with its length when wound. I

The pawl 27 may be pivotally mounted at 29 at one end of a bell crank member 30, which in turn is pivoted at 31. The pawl member 27 may be stamped from sheet metal into the form of a rigid channel member as indicated in Fig. 4 having a pair of perforated lugs at 32 for pivotal engagement with the bell crank member 30. A hook portion 33 may also be struck up from the channel member for engagement with the spring 28. The opposite end of the spring 28 may be made fast in respect to the frame parts in any desired manner. As here shown, however, provision is made for adjusting the tension of the spring 28 by providing a pin 34 passing through a slot 35 in the plate 22 and being adjustable within said slot in a direction longitudinally of the spring. (See Figs. 3, 6 and 7.) Suitable clamping nuts as at 36 are provided for securing the pin at the desired position along the slot 35. The slot 35 may be formed with its edges struck down as indicated at 37 to provide a channelway for receiving one of the clamping nuts and for retaining the nut against rotation.

The bell crank member 30 may be formed with an arm 38 adapted to be engaged by an armature portion 39 hereinafter described. The arm 38 may also be provided with a switch operating finger 40 hereinafter referred to.

The partsmounted upon the rear face of the plate 22 will now be described. An electro-magnet 41 is provided with a suitable winding having electrical characteristics depending upon the character of the electrical source of supply with which the device is intended to be used. This electrowith a pole face 47 at the end of the magnet core opposite from the screw 42. The crosssectional dimensions of the pole piece 43 may be effectively increased, particularly for a purpose hereinafter referred to, by a supplemental member 47 formed of magnetic material. The terminals of the winding of the electro-magnet 41 may be respectively attached to a terminal post 48 and a binding post 49.

The terminal post 48 is suitably insulated from the plate 22 by conventional insulation washers and is provided with a contact piece 50 of silver or other good contact making material and is designed to cooperate with a spring contact arm 51 which is electrically connected to the framework and thereby grounded for the return circuit. The contact piece 50 may be held in place upon the terminal post 48 by a suitable nut 52. The binding post 49 is also insulated from the plate 22 by conventional insulation washers and as here shown (see Fig. 6) is provided with a novel form of means for attaching a conductor thereto. It has been found to be desirable to introduce the conductor for carrying current to the magnet into the clock casing in a direction perpendicular to the plate 22 and to provide an attachment for such conductor whereby the conductor needs only to be rotated for detachment or to secure the same in position. The binding post hereinafter described has been found to fulfill these requirements in a simple and dependable manner. Referring again to Fig. 6, a binding screw 53 extends through the plate 22 in a direction from the front to the rear and is provided with a nut 54 for securin the same in position within the insulation washers 55. The end of the magnet wire 56 may be provided with a suitable terminal washer or may be wrapped around the screw 53 and held in such position by terminal member 57. This terminal member as shown is formed with an axial threaded aperture for receiving the screw 53 and at its opposite end is suitably recessed for receiving the end of a connecting wire 58. This recessed end of the terminal meniber may be suitably crimped or soldered to the end of the connecting wire. With this form of construction the connect" wire 58, which if desired may be of a re eiy lai size, may be introduced straight into the clock casing from the rear without bends or kinks which might interfere with the more delicate parts of the mechanism. After insertion, the wire 58 may be turned or twisted axially in order to bring its terminal member into firm engagen'ient with the magnet wire. VVit-h this form of conductor attaching means the electrical comiection may be very readily inserted and attached without disturbing the clock or taking it out of its casing.

An armature 59 cooperates with the pole faces 46 and 47 and is formed with the extension 39 above referred to (see Figures 4' and 8). A pair of armature supporting posts 60 and 61 extend upwardly from the plate 22 and are surmounted by a plate 62 within which a bearing 63 is provided for a rotatable post 64. The armature 59 is rotatably mounted: upon this post by means of a member-fihriveted as at 66 tothe armature and provided with suitable struck-up post 60 audits other end bearing against the armature member to normally hold the armature in spaced relation from the pole faces. Thepost .64 forms an extension of the pivoting means for the bell crank meanber 30, as above referredto, and designated by the numeral 31. I

i It will be noted that the spring 68seiwes to retract the armature 59 from the pole faces independently of the action of the main Q power spring 28. Accordingly, when the armature 59 is attracted to the pole faces upon energization of the electrosmagnet, the armature during the first part of its movement is relatively free to acquire a substantial momentum before the armature extension 39 comes into engagement with the bell crank arm 38. Upon engagement of the extension 39 with the arm 38, the bell crank 15 turned in .a manner to draw the pawl 27 28 will be wound or placed under greater tension. As soon as this action is accomplished, a switch mechanism hereinafter described will efiect an opening of the circuit of the electro-magnet thus permitting the armature to be retracted by the spring 68 and leaving the bell crank 30 andfpawl'27 to be gradually drawnaround by the spring 28 in a direction to rot-ate the ratchet wheel 26. It will he noted that the spring 68 is of relatively light construction and is not of suflicient strength to prevent the armature from acquiring substantial momentum durplate is further provided with a slot or ing the first part of its movement. The effective mot ve force of the magnet is mater1- ally augmented by reason of this momentum and accordingly during the latter part of the movement of the armature a power spring of considerable strength may be wound by the use of a magnet of relatively small dimensions. This permits ofa more compact construction than has heretofore been achieved with devices of this character. Furthermore, with this construction the power spring may be fully tensioned or wound during a very short interval of time. This permits of a clock construction of greater accuracy and dependability, AL so, the operation of the main spring isnot interfered with by any residual magnetism of the electro-magnet since when the magnet is de-energized the armature is disconnected from the bell crank 30 so that any tendency of the residual. magnetism to pull on the armature does not oppose the main spring 28. The armature does not act upon piece 43 above described, the armature ,59

end of the shaft is received in abearing 74 formed in the plate 22 i (see Fig. 7 )p. 4A

the main spring except when the magnet is fully energized.

Attention isalso directed to the magnetic circuit of the electroanagnet which comprises not only the core but also the, pole T and the pole faces 4C6 and-47. Although but a single electro-magnet coil is used, it will be notedthat the. magnetic circuit will be very nearly closed and hence particularly effective Justus the greatest load occurs duringthe winding of the main power spring.

The switch for controlling the current to so 3 and-9. The circuit to the electro-anagnet is made or. broken by the cooperating contacts5 0-and 51 above referred to. The, contact-50 is stationary,-whereas the spring I contact member or arm 51 may be rivetedfi as at 69 to a pivoted support 70 which is secured to a shaft 71. The shaft 71 is received by a bearing bracket '72 fastened to the plate 2.2 as by screw 73. The lower spiral spring .75 surrounds the shaft Tibetween thebearing bracket 72 and the rotatable support 70'and servesto normally'hias the spring contact arm 51 and its support f. toward the open circuit position. To effect this action the spring may have one end in 7 contact with the bearing bracket 72as shown and its other end in contact with-a struckup lug 7 6 formed upon the supporting plate ice 70. The supporting plate may be formed of magnetic material and provided with an integral struck-up armature portion 7 7 havingtwo faces at anglesto each other for cooperating. respectively with the rear of 4 pole face member 46 and the auxiliary pole piece 47 above referred to. The supporting will now be described. When the power spring is substantially unwound, the switch parts and armature will first be in their relative positions as shown in Fig. 3. Theswitch operatingfinger 40 will have come into contact with the outer side wall of the recess 78, thus causing the switch arm 51 to be moved to circuit closing posi-. tion against the action of the biasing spring 7 5. The magnet will thereupon be eners gized, causing theiarmature to be attracted in the'manner above outlined. Assoon as the armature extension 39. engages the bell crank member 30 the switch operating finger i will be drawn away from the side of the 77 provides a magnetic bypass and is attracted to the pole face and pole piece with sufficient force to withhold the biasing spring from acting. The auxiliary armature 77 also prevents the switch from accidental premature opening as by jarring. However, as the armature 59 approaches the pole faces 46 and 4:7 and the power spring becomes wound in the manner above described, the switch operating finger 40 will come into contact with the inner side wall of the recess 78. As a result, just as the power spring becomes wound, the finger 40 will force the supporting plate 70 and its contact 51 to open circuit position, as shown in dotted lines in Fig. 9, since the action of the main armature 59 will be sufficiently powerful to overcome the attractive force on the auxiliary armature 7 7. As the switch opens, the magnet will become deener gized, thus permitting the main armature to be retracted to normal position. Thereafter, during the succeeding minute the bell crank member 30 and the switch operating finger 40 will gradually move back to the positions indicated in Figures 3 and 4, the main spring driving the clock meanwhile. At the end of the minute this cycle of operation of the switch and armature is repeated.

With the form of switch above described, the various parts are kept under positive control during each part of the cycle of op eration. The switch is closed at the appropriate time and is kept closed for energizing the magnet until the power spring is completely wound to the desired extent. Thereupon the switch is positively opened.

Suitable securing bolts 79 for the casing may be formed integral therewith if desired. A clock time set-ting button of conventional construction is shown at 80.

While I have described my improvements in great detail with respect to a preferred form thereof, I do not desire to be limited to such details or form since many changes maybe made and the improvements embodied. in widely different forms. Hence, I desire to cover all forms coming within the language or scope of any one or more of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. Spring motor controlling mechanism comprising in combination an electro-magnet with an armature, means operated by said armature for winding the spring motor, and a switch operatively associated with the armature for controlling the electro-magnet, said armature being attracted toward the pole pieces upon energizatlon of the electro-magnet and being relatively free to acquire momentum during the first part armature for winding the spring motor, and a switch operatively associated with the armature for controlling the electro-magnet, said armature being attracted toward the pole pieces upon energization of the electromagnet and spring winding means being positioned to be first engaged by said armature during the latter portion of movement whereby the electro-magnetic force in addition to momentum of the armature is then imparted to the spring motor.

3. In an electric ciock, the combination with an electro-magnet of an armature therefor, a main spring, means engaged by the armature after its initial movement when attracted by the magnet for winding the main spring, said ari'nature being disconnected from and ineffective on said winding means when the magnet is de-energized.

4. In an electric clock, the combination with an electro-magnet of a pivoted arma ture therefor, a main power spring, and a pivoted lever connected to said spring, said armature being provided with a portion engaging said lever bnt only after the armature is set in motion by the magnet, such engagement effecting a movement of the lever for winding the spring.

5. In an electric clock, the combination with an electro-magnet of an armature pivotally mounted upon a shaft, a main power spring, and a lever connected to said spring and also pivotally mounted upon said shaft, said armature being movable about its mounting independently of said lever and being provided. with a portion for striking said lever during the latter part of its movement after the magnet is energized for attracting the armature, such striking effecting a movement of the iever for winding the spring.

6. In an electric clock, the combination with an electro-n'iagnet of an armature pivotally mounted upon a. shaft, a main power spring, a lever connected to said spring and also pivotally mounted upon said shaft, said armature being movable about its mounting independently of said lever and being provided with a portion for striking said lever during the latter part of its movement after the magnet is energized for attracting the armature, such striking effecting a movement of the lever for winding the spring, and a spring for immediately restoring and normally maintaining said armature at a position spaced from the magnet pole pieces.

7. In an electric clock, the combination with an electro-magnet of a resiliently controlled striking armature therefor, a main power spring, a pivotally mounted lever con nected to said spring, said armature being provided with a portion for engaging said lever when the magnet is energized for attracting the armature, such engagement ei" fecting a movement of the lever for Wind- H ing the spring, and a switch for controlling the circuit of the magnet, said lever as moved by said armature and said power spring respectively acting to open and close said switch.

2 8. In an electric clock, an electro-magnet winding with a core therein having one end which comprises a pole face, a suitably shaped pole piece secured to the other end of said core and extending longitudinally of the core and terminating in a fiat portion forming another pole face in alignment with the first, an armature for cooperating with the pole faces when the magnet is energized for winding the clock, a switch in :11, the circuit of the electro-inagnet, and an auxiliary switch controlling armature associated therewith forming an increased magnetic path for said suitably shaped pole piece.

a: In testimony whereof I have signed my name to this specification.

LEWIS J. STERN. 

